The invention relates to the use of laser radiation to promote or enhance vascular or other growth in a thus-irradiated local area of living body tissue.
In their paper, "Some New Findings on Retinal Irradiation by Krypton and Argon Lasers",* J. Marshall, et al. review the histopathology of the acute effects of krypton and argon laser radiation on the human retina, and these effects are related to their long-term pathology by observations on diabetics. Emphasis was on laser photocoagulation but some "surprising findings" were reported involving proliferation of vascular endothelial cells adjacent the reaction site. And in a later paper, "He-Ne Laser Stimulation of Human Fibroblast Proliferation and Attachment in Vitro",** coauthored by J. Marshall, laboratory studies are reported for laser-irradiated cultures of excised human tissues, wherein the irradiation source was a 1 mW helium-neon laser providing a coherent source at 633 nm, wherein the irradiation was chopped at 100 Hz, to provide a 50 percent duty cycle; for each experiment, a comparative run was made involving monochromatic incoherent light via a 640-nm interference filter (bandwidth 9 nm), adjusted for intensity comparable with that of laser delivery to an identical culture. The reported result was that, at 24 and at 48 hours after 15-minute exposure, the particular laser-irradiated cultures exhibited a significant increase in the number of cells in comparison with their respective non-irradiated controls, while no significant change in cell counts was observed between irradiated and control cultures in experiments with the incoherent source. FNT * Docum. Ophthal. Proc. Series, Vol. 36, pp. 21-37, 1984, Dr. W. Junk Publishers, The Hague. FNT ** Lasers in the Life Sciences 1(2), 1986, pp. 125-134, Harwood Academic Publishers GmbH.